β-Lactam and penicillin substituted mesoionic metal carbene complexes.

1,2,3-Triazolylidene MIC M-complexes (M = Au, Pd, Pt) having 2-azetidinones and penicillin G substituents at the triazole ring were prepared by CuAAC on 2-azetidinones having a terminal alkyne tethered at N1, followed by alkylation of the 1,2,3-triazole ring and transmetallation [Au(I), Pd(II) and Pt(II)]. The Au-MIC complexes efficiently catalyze the regioselective cycloisomerization of enynes, while the Pt-MIC complexes were efficient catalysts in hydrosilylation reactions.